Eevee or similar in 2.79
The closest this that exists that I am aware of is a prototype that led to Eevee (Clement Foucault's pbr viewport branch):
http://www.clement-foucault.com/#blender_pbr / https://github.com/Hypersomniac/blender-shader

It has a bunch of nice improvements on the old viewport but is still very much a prototype. It is also based on an older version of blender than 2.79 (still in the 2.7Xs though). 

All that said, I'd recommend trying to persevere with 2.8, and pin down exactly what you don't like / become familiar with the changes. Dislike can often come just from a lack of familiarity, it may only need a few settings tweaks and a bit of practice to be fine.